"Jay Honeck" wrote in message news:
And mechanical failures should have simple explanations, no? WHY did
one of the cam lobes fail? Why didn't ALL of the cam lobes fail?

Timeless issue. www.aviationconsumer.com has hours of reading on the
subject. The common factor is infrequent flying.

I suppose the *real* issue should be: Why do camshafts work at all? When
you sit down and rationally analyze what is happening inside your engine,
the danged thing should just throw itself to pieces in the first ten
minutes of operation.

Yet, most of them don't.

Some, however, like Ray's engine, do -- and in very peculiar ways. (Just
ONE cam lobe went bad?)

I've gone through a couple on one engine and they had those exact symptoms.
One AME suggested that the front lobes wear more quickly since the cam is
slightly elevated at the front so the oil drains off more quickly. There
are as many theories as worn cams, it sometimes seems.

moo